PD19-10: MANAGEMENT OF TESTICULAR GERM CELL TUMOR WITH SECONDARY SOMATIC MALIGNANCY PRESENT IN THE ORCHIECTOMY

Nathan C. Wong, Shawn Dason, Lucas W. Dean, Tim N. Clinton, Sumit Isharwal, Mark T.A. Donoghue, Sujata Patil, Liwei Jia, William D. Tap, Gabriella Joseph, Samuel Funt, Deaglan McHugh, Hikmat Al-Ahmadie, George J. Bosl, Joel Sheinfeld, David B. Solit, Darren R. Feldman

Introduction: Testicular germ cell tumors (GCT) will rarely contain teratoma with secondary somatic malignancy (SSM). Little is known about the clinical implications of this finding in the primary testicular specimen. For this reason, we report the Memorial Sloan Kettering Cancer Center (MSKCC) experience with testicular SSM.

Methods: Institutional databases were reviewed to identify patients with testicular SSM assessed from 1985 to 2018 at MSKCC. The diagnosis of SSM was confirmed in all cases by an experienced genitourinary pathologist and clinical data was reviewed retrospectively. The Kaplan-Meier method was used to estimate overall survival.

Results: Fifty-nine patients with testicular SSM were identified, of which 15 had pathology review only with limited clinical information. The median age at presentation was 27 years (range 17-69) and median follow-up for survivors of 3.9 years (range 0.4-23.3 years). Patients were evenly distributed by clinical stage (CS) [CS1 (32%), CS2 (34%), and CS3 (34%)]. The most common SSM histologies were sarcoma (63%) and primitive neuroectodermal tumor (22%). Of 13 CS1 patients, 12 underwent primary retroperitoneal lymph node dissection (RPLND) with long term survival while the 1 patient who underwent surveillance relapsed in the retroperitoneum and eventually died of disease. Of 34 patients with CS 2/3 disease, 79% had elevated markers and 94% had retroperitoneal disease. Similar to patients with metastatic GCT without SSM, those with elevated markers were generally treated with GCT-directed chemotherapy regimens followed by RPLND and resection of any other residual disease. SSM histology-directed chemotherapy was generally reserved for adjuvant treatment of resected SSM and for unresectable disease lacking evidence of residual GCT. Estimated 5-year overall survival was: CS1 100%, CS2 92% (1 death of disease), and CS3 76% (3 death of disease) [Log rank p=0.01 CS3 vs. CS1/2].

Conclusions: Patients with clinical stage 1 testicular GCT containing SSM have an excellent prognosis when managed with orchiectomy and primary RPLND. Clinical stage 2/3 GCT with SSM in the testis are managed similarly to patients without SSM, with an emphasis on PC-RPLND and resection of extra-retroperitoneal post-chemotherapy masses. Source of

Funding: This research was supported by the Sidney Kimmel Center for Prostate and Urologic Cancers and funded in part through the NIH/NCI Cancer Center Support Grant P30 CA008748.